Sparks from workers using a sawzall to remove an exhaust system from a van ignited flammable liquids spilled on the floor early this morning. Engines 2,1,11 Ladder 1, Squad 1, Rescue 1, and Battalion 1 were dispatched to a structure fire around midnight. Dispatchers advised a car was on fire inside the shop. On arrival Engine 2 reported heavy fire through the roof with heavy smoke conditions. E-2 layed in and lead off with a 2 1/2. A 2nd alram was requested on making entry due to heavy fire conditions. E-1 pulled a back-up line while E-11 stood by as the F.A.S.T. team. Sq-1 forced entry to an adjoining business to check on extension as L-1 made way to the roof for ventilation. The bulk of the fire was knocked down with in 15 mins. with overhaul taking several hours.